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SubjectRe: [PATCH 0/7] cputime: Full dynticks task/cputime accounting v5
Right...  Replied to the wrong email.  :-/

I queued "context_tracking: Add comments on interface and internals".

Thanx, Paul

On Fri, Jan 25, 2013 at 09:42:47AM -0800, Paul E. McKenney wrote:
> On Thu, Jan 17, 2013 at 02:24:28PM +0100, Frederic Weisbecker wrote:
> > Hi,
> >
> > This patchset was formerly called "Generic virtual based cputime accounting"
> > but I changed the name to better reflect what it's all about.
> >
> > This is the part of the full dynticks patchset that handles the task and CPU
> > time accounting without the tick.
> >
> > It's available at:
> >
> > git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git
> > vtime/generic-v5
> >
> > There have been a lot of changes since latest full dynticks patchset:
> >
> > - Use sched_clock() instead of jiffies for better precision. And because
> > jiffies granularity was requiring too much dirty hacks to make it working.
> > (Thanks Steven for the suggestion).
> >
> > - To fully support sched_clock(), use a per nanosec granularity in cputime_t
> >
> > - Fix a deadlock with tsacct
> >
> > - Better description of the Kconfig
> >
> > - Don't scale generic vtime accounting against CFS precise task time accounting.
> > Now that we use sched_clock() we should have precise enough statistics.
> >
> > - Consolidate some code in the reader side
> >
> > - Make the reader irqsafe (fix potential deadlock against writers)
> >
> >
> > Most of the work is done. There are just a few small things I need to care about
> > to complete the full cputime support:
> >
> > * Also handle dynticks guest time accounting (p->gtime and p->utime). This
> > require to bring a new accessor: task_gtime() and to add guest_enter() and
> > guest_exit() on the context tracking subsystem. Then make the same treatment
> > than with utime and stime. No big deal.
> >
> > * New tasks start their cputime accounting from schedule() on sched-in time
> > (see arch_vtime_task_switch()). But I fear that idle tasks don't fall into this
> > category. That's a small detail but I hope I can find some generic way to handle it.
> > The boot init idle task is however handled.
> >
> > * Per nsec granularity requires that cputime_t directly maps to cputime64_t. This
> > is fine on 64 bits archs and mostly fine in 32 bits archs as well because readers
> > use seqlock to synchronize against writers. But reading struct kernel_cputstat
> > is not protected. Not sure yet how to solve that.
> >
> > So I'll likely focus on these items on the next version. Let's hope we can make
> > it ready for the next merge window.
>
> Queued for 3.9, thank you!
>
> Thanx, Paul
>
> > Thanks.
> >
> > ---
> > Frederic Weisbecker (7):
> > context_tracking: Export context state for generic vtime
> > cputime: Librarize per nsecs resolution cputime definitions
> > cputime: Move default nsecs_to_cputime() to jiffies based cputime file
> > cputime: Generic on-demand virtual cputime accounting
> > cputime: Allow dynamic switch between tick/virtual based cputime accounting
> > cputime: Use accessors to read task cputime stats
> > cputime: Safely read cputime of full dynticks CPUs
> >
> >
> > arch/alpha/kernel/osf_sys.c | 6 +-
> > arch/ia64/include/asm/cputime.h | 92 +----------
> > arch/ia64/include/asm/thread_info.h | 4 +-
> > arch/ia64/include/asm/xen/minstate.h | 2 +-
> > arch/ia64/kernel/asm-offsets.c | 2 +-
> > arch/ia64/kernel/entry.S | 16 +-
> > arch/ia64/kernel/fsys.S | 4 +-
> > arch/ia64/kernel/head.S | 4 +-
> > arch/ia64/kernel/ivt.S | 8 +-
> > arch/ia64/kernel/minstate.h | 2 +-
> > arch/ia64/kernel/time.c | 4 +-
> > arch/powerpc/configs/chroma_defconfig | 2 +-
> > arch/powerpc/configs/corenet64_smp_defconfig | 2 +-
> > arch/powerpc/configs/pasemi_defconfig | 2 +-
> > arch/powerpc/include/asm/cputime.h | 6 +-
> > arch/powerpc/include/asm/lppaca.h | 2 +-
> > arch/powerpc/include/asm/ppc_asm.h | 4 +-
> > arch/powerpc/kernel/entry_64.S | 4 +-
> > arch/powerpc/kernel/time.c | 4 +-
> > arch/powerpc/platforms/pseries/dtl.c | 6 +-
> > arch/powerpc/platforms/pseries/setup.c | 6 +-
> > arch/s390/kernel/vtime.c | 6 +-
> > arch/x86/kernel/apm_32.c | 11 +-
> > drivers/isdn/mISDN/stack.c | 7 +-
> > fs/binfmt_elf.c | 8 +-
> > fs/binfmt_elf_fdpic.c | 7 +-
> > include/asm-generic/cputime.h | 66 +-------
> > include/asm-generic/cputime_jiffies.h | 72 +++++++++
> > include/asm-generic/cputime_nsecs.h | 104 ++++++++++++
> > include/linux/context_tracking.h | 28 ++++
> > include/linux/hardirq.h | 4 +-
> > include/linux/init_task.h | 11 ++
> > include/linux/kernel_stat.h | 2 +-
> > include/linux/sched.h | 34 ++++
> > include/linux/tsacct_kern.h | 3 +
> > include/linux/vtime.h | 51 ++++--
> > init/Kconfig | 23 +++-
> > kernel/acct.c | 6 +-
> > kernel/context_tracking.c | 22 +--
> > kernel/cpu.c | 4 +-
> > kernel/delayacct.c | 7 +-
> > kernel/exit.c | 6 +-
> > kernel/fork.c | 14 ++
> > kernel/posix-cpu-timers.c | 28 +++-
> > kernel/sched/cputime.c | 219 +++++++++++++++++++++++---
> > kernel/signal.c | 12 +-
> > kernel/softirq.c | 6 +-
> > kernel/time/tick-sched.c | 5 +-
> > kernel/tsacct.c | 44 ++++--
> > 49 files changed, 696 insertions(+), 296 deletions(-)
> > create mode 100644 include/asm-generic/cputime_jiffies.h
> > create mode 100644 include/asm-generic/cputime_nsecs.h
> >
> > --
> > 1.7.5.4
> >



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